I know I've probably fucked up the math, but can't bring myself to care enough to do a deep dive, but here goes: the chances of none of them offing themselves before the kid hits the teenage years or so is about 58% x 58% x 58%, or just under 20%. If we're really lucky, one of them will go for a triple header, and kill three birds* with one stone. *apologies to our resident stupidbird, it's just a figure of speech.